Semaphore switch-stand.



No. 824,869. PATLNTLD JULY s, 1906. I. D. ISAAGS, W. W. SLATLP. a. M. L. -DANILLS- 2l SHEETS-SHEET 1.

SEMAPHORE SWITCH STAND.

APPLICATION FILED Mmm. 1906.

Maz/1,869. PATENTBD JULY s, 1906. J. DISAAGS, W.. W. SLATER al M. R. DANIELS. SBMAPHORE SWITCH STAND.

APPLICATION FILED MAR.24, 1906.

2 SHEBTS-SHEETZ.

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'UNITED STATES PATENT OFFICE..

JOHN D. ISAACS, OF OAKLAND, AND WILLIAM W. SLA'ER AND MARK R. DANIELS, OF SAN FRANCISCO, CALIFORNIA.

SENIAPHORE SWITCH-STAND.

Nose-1,869.

Specification of Letters Patent.

Patented July 3, 1906.

Application iiled March 24.1906. Serial No. 307,944.

To (IJ/Z whom, t may concern:

Be it known that we, JOHN Dovn IsAAos, of the city of Oakland, county of Alameda, and WILLIAM W. SLATER and MARK R. DAN- iELs, of the city and county of San Francisco, State of California, have invented certain new and useful Improvements in Semaphore Switch-Stands, and we do hereby declare the following to be a full, clear, and exact description of the same.

Our invention relates to the class of semaphore switch-stands; and it consists, in connection with the lever having the double function of operating both the track-switch and the semaphore-spectacles, of intervening mechanism for effecting the change of the spectacles only approximately at the moment the track-switch reaches or departs from a safety position.

The object of our invention is to insure the change of the spectacles at the most timely moment, which moment is that at which the switch reaches or departs from safety, as we shall hereinafter demonstrate.

Referring to the accompanying drawings, Figure 1 is an elevation, partly in section, of our semaphore switchlstand, showing the back spectacle at safety, the front spectacle and blade being removed. Fig. 2 is an elevation, partly in section, of the switch-stand at right angles to the elevation of Fig. 1. Fig. 3 is a plan view of our semaphore switchstand, on a smaller scale. Fig. 4 is an elevation of the same, the spectacles and blade being at safety, dotted lines showing the movement to dangen Fig. 5 is a side view of the operating mechanism, showing the parts in a position for safety. Fig. 6 is a similar view showing the operating-cam lifted by crank at the beginning of its stroke.

1 is the switch-stand base, upon which in suitable bearings 2 is mounted the rocking semaphore-shaft 3. To one end of this shaft is connected the switch-lever 4, having a pin 5, on which is mounted the connecting-rod 6, which is here shown broken away, but which may be supposed to extend to and to be connected with the throw-rails of the trackswitch, which it is deemed unnecessary herein to show, in the usual manner.

Rising from the stand-base 1 is the semaphore-post 7 which carries at its top the lantern 8, having the usual plain-glass lights 9. *Mounted to rock in the upper portion of the post 7 is the spectacle-shaft 10, on the ends of which are the spectacle-castings 11, one being the front spectacle and the other the back spectacle. Each casting 11 carries the usual red glass 12 and the green glass 13,

I adapted to be severally alined with the lantern-lights 9, as usual, according to the necessities of the case. The movement of vthe spectacles is due to the rocking of shaft 10, which rocking is effected by means of the crank 14 on said shaft and the up and down rod 15 in the post 7.

To the spectacle-casting is fitted the usual semaphore-blade 16 for a daylight signal.

The parts thus far described are those in general of the usual dwarf ysemaphore switchstand.

Heretofore in such devices the duplex function of the switch-lever 4-to wit, that of operating the track-switch and that of operating the spectacleshas been open to the objection that the two operations or movements are what may be termed relatively synchronous throughout-that is, the throwrails of the switch are going through their movement at the same relative rate as the spectacles are performing their movement. The result of this may be seen from an example-as, for instance, suppose the spectacle and the switch to be set for safety in a particular case. 4Now when the switch-lever commences its movement toward danger both the spectacle and the switch begin their movement toward a like condition; but while the spectacle may take some moments prior to reaching its limit, where it shows danger, the switch instantly becomes dangerous the moment it begins to depart from safety` The spectacle and switch are therefore not in harmony at the start. The reverse illustration may also be givento wit, suppose the spectacle and switch be set for danger Then in throwing the spectacle for safety it departs from danger some moments before the switch has reached safety, for of course the switch is never safe except at its limit, and the slightest movement from this limit represents dangerf7 To obviate this difficulty, we destroy by our invention this relative synohronosity of the two movements by giving to the spectacle its full functional movement by a quick change, timed approximately to the limit of the switchthrow, whereby the spectacle indicates with IOO the maximumaccuracy the instant the throwrails of the switch reach safety or depart therefrom.

In the present case the means preferred are as follows: Pivoted to a bearing 17 on the base 1 is a swinging cam'18. This cam has the form of a curved lever, the pivotal connection being near one extremity, while the other extremity has connected with it the up and down rod 15. The end of the cam 18 near its pivotal connection is formed on a curve, as indicated at 19, eccentric to the shaft 3, while the remainder of said cam has its face concentric with said shaft. Upon I shaft 3 is a crank 20, in the end of which is an antifriction-roller 21, which impinges upon cam 18.

The arrangement of the cam relatively to the parts which operate it and which it operates is such that when the switch-lever is substantially horizontal the crank 2O is likewise horizontal and its roller 21 lies in the eccentric face or end 19 of cam 18, thereby depressing said cam to itslower limit. In this position the spectacles are set for safety and the switch is closed. Now upon lifting the switch-lever the first effects are two-to Wit, to begin to throw the switch-rails and at the same time-that is, at the very beginning of the movement of the switch-to instantly throw the spectacles fully to danger. This is due to the action of the crank 20 on the eccentric portion 19 of cam 1S, which cam is thereby thrown up to its limit, and through the rod 15 the cam operates the spectacles. Thereafter the continued movement of the switch-lever while it fully operates the switch has no effect on the spectacles, because the roller 21 is traveling on the concentric face of the cam and merely holds the parts in their position. Thus the semaphorespectacles are fully operatedthe instant the switch begins to move. Reversely, when the switch-lever is thrown down again there is at first only one eifect-namely, to begin to operate the switch; but the spectacle remains at danger and should do so, because the switch is not safe until it reaches its limit but when about to reach this limit, and consequent safety, the roller21 reaches the eci centric face 19 of cam 18, and just as the switch closes the spectacles are moved to safetyf7 Thus the semaphore remains at danger until the switch reaches safety, when at the same instant it is operated to indicate the fact.

Having thus described the invention, what we claim as new, and desire to secure by Letters Patent, is`

1. In a semaphore switch-stand, the combination of a switch-lever, a connection from the lever to operate the switch, a semaphorev spectacle, a rod and connections to operate the spectacle, and intervening connections between the switchboard and spectacle-rod adapted to operate the spectacle only approximately at the moment the switch reaches or departs from the safety position, consisting of arock-shaft to which the switchlever is connected, a swinging cam, to which the spectacle-rod is connected, and a crank on the rock-shaft for operating said cam.

2. In a semaphore switch-stand, the combination of a switch-lever, a connection from the lever to operate the switch, a semaphorespectacle, a rod and connections to operate the spectacle, and intervening connections between the switchboard and spectacle-rod adapted tooperate the spectacle only approximately at the moment the switch reaches or departs from the safety position, consisting of arock-shaft to which the switchlever is connected, a swinging cam, to which the spectacle-rod is connected, said cam having one end eccentric to said shaft and the remainder concentric therewith, and a crank on the rock-shaft for operating said cam.

In witness whereof we have hereunto set our hands.

JOHN D. ISAACS. WILLIAM W. SLATER. MARK R. DANIELS.

Witnesses to signatures of Isaacs and Slater:

JAMES C. YOUNG, ARCI-IIE W. HEWITT.

Witnesses to signature of Daniels:

WALTER FARNHAM, D. G. KLINEFELTER. 

